By Jesse Bering It may seem to you that, much like their barnyard animal namesake, men’s reproductive organs the world over participate in a mindless synchrony of stiffened salutes to the rising sun. In fact, however, such "morning wood" is an autonomic leftover from a series of nocturnal penile tumescence (NPT) episodes that occur like clockwork during the night for all healthy human males—most frequently in the dream-filled rapid eye movement (REM) periods of sleep from which we’re so often rudely awakened in the A.M. by buzzers, mothers, or others. For those with penises, you may be surprised to learn how frequently your member stands up while the rest of your body is rendered catatonic by the muscular paralysis that keeps you from acting out your dreams. (And thank goodness for that. Carlos Schenck and his colleagues [pdf] from the University of Minnesota Regional Sleep Disorders Center describe the case of a 19-year-old with sleep-related dissociative disorder crawling around his house on all fours, growling, and chewing on a piece of bacon—he was ‘dreaming’ of being a jungle cat and pouncing on a slab of raw meat held by a female zookeeper.) Scientists have determined that the average 13- to 79-year-old penis is erect for about 90 minutes each night, or 20 percent of overall sleep time. With your brain cycling between the four sleep stages, your "sleep-related erections" appear at 85-minute intervals lasting, on average, 25 minutes. (It’s true; they used a stopwatch.) I didn’t come upon any evolutionary theories or a proposed "adaptive function" of NPT, but we do know that it’s not related to daytime sexual activity, it declines (no pun intended) with age, and it’s correlated positively with testosterone levels. Females similarly exhibit vaginal lubrication during their REM-sleep, presumably with many dreaming of erect penises. Now, you may not think that such tedious biological details would be fodder for a moral quandary, but you underestimate our species’ massive confusion when it comes to understanding how its coveted free will articulates with its genitalia. © 2011 Scientific American

Keyword: Sleep; Sexual Behavior
Link ID: 15359 - Posted: 05.24.2011

By Larry Greenemeier Nanoparticles have been investigated in recent years as tools for defending the brain against neurotoxic proteins that may contribute to the onset of several different neurodegenerative disorders including Alzheimer's disease. Such proteins, in particular amyloid-beta peptides, are thought to play a role depositing fibrous plaques on the brain that damage synapses (the contact points between neurons) and lead to a decline in cognitive capabilities. During the onset of Alzheimer's, amyloid beta collects in the brain centers that form new memories. As the disease progresses, these toxic protein fragments block neurotransmitters from reaching receptors on neurons. The promise of nanoparticles is that their capacity to mimic some biological functions as well as penetrate the blood–brain barrier will enable them to stop the growth of neuron-blocking fibrils better than drug compounds that might contain some variation of short peptides, antibodies or proteins—such as human serum albumin (HSA) protein. (There currently are no anti-Alzheimer's drugs on the market.) Whereas such compounds have been shown to interfere with fibril formation, researchers are hoping that inorganic nanoparticles can do so more effectively. Although the nanotech approach has great potential, the challenges are many, including finding a nanoparticle material that is effective yet also biocompatible and nontoxic. Another source of controversy: some nanoparticles that have been studied, including quantum dots and carbon nanotubes, seem to actually promote or accelerate fibrillation rather than prevent it. © 2011 Scientific American,

Keyword: Alzheimers
Link ID: 15358 - Posted: 05.24.2011

Crossing your arms across your body after injury to the hand could relieve pain, researchers suggest. The University College London team, who undertook a proof-of-concept study of 20 people, say the brain gets confused over where pain has occurred. In the journal Pain, they suggest this is because putting hands on the "wrong" sides disrupts sensory perception. Pain experts say finding ways of confusing the brain is the focus of many studies. The team used a laser to generate a four millisecond pin-prick of pain to participants' hands, without touching them. Each person ranked the intensity of the pain they felt, and their electrical brain responses were also measured using electroencephalography (EEG). The results from both participants' reports and the EEG showed that the perception of pain was weaker when the arms were crossed over the "midline" - an imaginary line running vertically down the centre of the body. Dr Giandomenico Iannetti, from the UCL department of physiology, pharmacology and neuroscience, who led the research, said: "In everyday life you mostly use your left hand to touch things on the left side of the world, and your right hand for the right side of the world. BBC © 2011

Keyword: Pain & Touch
Link ID: 15357 - Posted: 05.24.2011

By RICHARD A. FRIEDMAN, M.D. No sooner had Dominique Strauss-Kahn been arrested on sexual assault charges in New York than a parade of psychiatrists stepped forward to offer their expert opinion in the news media. Mr. Strauss-Kahn, who subsequently resigned as chief of the International Monetary Fund, will experience “a terrible grief because he is in prison,” said one. Another offered that he would have “terrible mourning” for “the loss of social status, image and glory.” Of course, it’s only natural for the media to seek comment from experts. But as a psychiatrist, I cringe at statements like these, for they cross an ethical line that goes back to a presidential campaign nearly half a century ago. Just before the 1964 election, a muckraking magazine called Fact decided to survey members of the American Psychiatric Association for their professional assessment of Senator Barry Goldwater of Arizona, the Republican nominee against President Lyndon B. Johnson. Ralph Ginzburg, the magazine’s notoriously provocative publisher, had heavily advertised the issue in advance, saying it would call Mr. Goldwater’s character into question. A.P.A. members were asked whether they thought Mr. Goldwater was fit to be president and what their psychiatric impressions of him were. It was not American psychiatry’s finest hour. © 2011 The New York Times Company

Keyword: Schizophrenia; Depression
Link ID: 15356 - Posted: 05.24.2011

By SEAN B. CARROLL I am not a big fan of reality TV, but I will confess that I am a loyal viewer of the Discovery Channel’s “Deadliest Catch” series. The show chronicles the adventures of the crews of several crabbing boats of the Alaskan fleet as they pursue red king crabs on the Bering Sea. What fascinates me, and I suspect other viewers, is the vicarious experience of watching the crews working for long stretches in unimaginable conditions. I know that this landlubber would not last an hour on any boat as it heaved in 30-foot seas, let alone while hauling 800-pound crab pots on an ice-covered deck, in 60-mile-an-hour winds, for 20 to 30 hours straight. That’s definitely not for me. My crab-catching is limited to plucking hermit crabs the size of golf balls off the sands of some quiet Florida beach in 80-degree weather. One might think that not only is there no comparison between my beachcombing and the dangerous business of Alaska crab fishing, but that the two kinds of crabs involved have very little in common. The typically diminutive hermit crabs have to contort their bodies into abandoned snail shells, while the four- to nine-pound red king crabs, the largest of the more than 100 species of king crabs, freely prowl the ocean bottom in search of worms, clams, mussels, starfish and other prey. Looking at those monsters of the deep, safely steamed on your plate at Red Lobster, one might think that such tasty beauties would be more closely related to other crabs on the menu, like stone crabs, than to the largely inedible hermit crabs. © 2011 The New York Times Company

Keyword: Evolution
Link ID: 15355 - Posted: 05.24.2011

by Sara Reardon The pianist's languid solo entwines itself with the smoke and the muffled laughter from the bar. Like a shadow, the musician's fingers glide effortlessly across the keys, and he has no sheet music in front of him. Has he memorized the piece, or is he making it up as he goes along? It’s almost impossible to tell, but if you're a jazz musician and can imagine yourself playing the music, your brain’s emotional centers might help you answer this question, a new study suggests. The ability to distinguish planned actions from spontaneous ones helps us judge whether a person is deliberately lying and might also help us value creativity. But it’s unclear how the brain makes these judgment calls, especially when it has little context to work with. To study how musicians judge spontaneity, psychologists Annerose Engel and Peter Keller of the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, recorded six jazz pianists as each one played improvised jazz over a backing track. Then the researchers transcribed the pieces, handed out the sheet music, had the pianists practice until they could replicate their colleagues’ improv perfectly, and recorded their performances. A computer analysis of the recordings showed that each improvised piece was more erratic in its loudness and speed than its rehearsed counterpart. So a machine could tell the difference between the improvised solos and the rehearsed reproductions. But could another musician? When a second set of 22 jazz musicians listened to all the improvised and rehearsed pieces in a random order, they could correctly guess which was which only about 55% of the time—only slightly better than chance—the researchers report in Frontiers in Psychology this month. However, the guessers who rated themselves in a questionnaire as more “empathetic” were better at picking out the improvisations. Similar correlations held true of those who had played with bands, as opposed to playing only as soloists. © 2010 American Association for the Advancement of Science.

Keyword: Emotions; Hearing
Link ID: 15354 - Posted: 05.24.2011

Sperm whales speak in distinct regional dialects that appear closely linked to different "cultural groups," a Canadian researcher says. "The animals in the Caribbean sound different than the animals in the Pacific — even the Gulf of Mexico, which is right beside the Caribbean," said Shane Gero, a researcher at Dalhousie University in Halifax. "In a lot of ways, that's very similar to us. We can identify someone from the U.K. versus Canada because they say 'lorry' and not 'truck.'" Sperm whales from many different regions meet in some "multicultural" areas of the ocean but tend to associate with whales that speak their own dialect, Gero told CBC's Quirks & Quarks in an interview that airs Saturday. "Their society really is divided based on culture," he said. "Animals that have different dialects behave differently. They feed on different things. They raise their babies differently." Gero has been studying sperm whales in the Caribbean for his PhD thesis. He and his collaborators in Canada and Scotland have been trying to decode sperm whale language by recording the voices of pairs of animals talking to one another and noting differences among the sounds they make. Female sperm whales spend all year in family groups in subtropical regions of the ocean, while males roam all over the world. When two whales encounter each other, they make patterns of clicks called codas. © CBC 2011

Keyword: Animal Communication; Evolution
Link ID: 15353 - Posted: 05.21.2011

By Deborah Kotz, Binge drinking has been named by university presidents as the single biggest problem on college campuses, responsible for accidental injuries, unintended pregnancies, date rapes, and alcohol poisoning. If that's not enough to stop students from drinking excessively, perhaps they'll be influenced by this new Spanish study: College students who binge drink have a slightly lowered ability to remember lists of words when the alcohol wears off compared with those who don't binge drink. While it's not clear from the study if binge drinking actually caused these memory defects, this and previous research "supports that possibility," says Aaron White, a college drinking prevention researcher at the US National Institute on Alcohol Abuse and Alcoholism who is familiar with the study. And that could mean that students, say, have trouble remembering a list of dates for history class or an equation in math class. How many drinks is a binge? Five or more servings of alcohol in a day for a man and four or more servings for a woman, according to Harvard researchers who studied alcohol's effects on different genders. A serving of alcohol is defined as 12 ounces of beer, 8 ounces of malt liquor, 5 ounces of wine, or 1.5 ounces, or a shot, of spirits or liquor (rum, vodka, whiskey). "This is not about getting drunk one time but binging with some regularity," says White. "The strongest evidence we have suggests that those at greatest risk for memory impairment drink heavily and often -- often to the point of developing withdrawal symptoms." © 2011 NY Times Co.

Keyword: Drug Abuse; Learning & Memory
Link ID: 15352 - Posted: 05.21.2011

Fix your eyes on the red dot in the animation above. As the circular pattern turns, it may appear to jump backwards but the skipping motion is all in your mind. What's actually happening in this illusion, created by Mark Wexler from Paris Descartes University, France, is that the random lines that make up the circle are suddenly replaced by a different pattern. In the video above, you can see a few variations of the illusion that demonstrate that the effect is perceived regardless of the rotation's direction. "The jumps can also be seen if white lines are suddenly made black and vice versa," says Wexler: "If the lines are randomised again for a slightly longer duration, the jumps seem to go further back." There is currently no known explanation for this brain trick. But Wexler thinks it's a type of motion after-effect, with two main differences. Typically, the illusory motion is much slower than the main one but in this case it's extremely fast. In addition, many observers reported a change in amplitude accompanying the switch whereas motion after-effects don't usually involve a change in position. By making the change of pattern occur more slowly, Wexler found that many people perceived a net motion in the opposite direction to the original rotation. He says: The illusory motion is more pronounced than the (real) motion we put in: a perceptual, perpetual motion machine! © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 15351 - Posted: 05.21.2011

by Miguel Nicolelis ANSWER quickly: what links the internet, the stock market, democratic elections, a perfect soccer play, the big bang theory, the frescoes of the Sistine Chapel and the iPad? Most people guess that the only possible link is they are all created by humans. While this is technically correct, it doesn't credit the true creator of such macro structures and exquisite tools: the human brain. As well as the almost infinite catalogue of artificial tools and beliefs that rule most of our lives, our cherished social, political, and economic systems also blossom as by-products of the incessant electrochemical storms brewed by the brain circuits formed by billions of interconnected cellular elements. These neurons make up an organic structure so majestic and mysterious that its only true rival in complexity and power is the cosmos that hosts us all. For the past 200 years or so, neuroscientists have been obsessed with understanding how the roots of all our glory and disgrace, as individuals and as a species, emerge from waves of neuronal electrical activity that propagate through a neural ocean. Just how do they morph into what is conventionally known as thinking, the main currency of our primate brains? In the early 19th century, Franz Joseph Gall in Germany and Thomas Young in Britain pioneered the modern age of neuroscience with opposing theories of how the brain worked. Gall's phrenology proposed that brain functions were localised in particular spatial territories of the human cortex, the most superficial part of the nervous system, just beneath the skull. Gall and his disciples made a living by claiming to ascertain the key personality traits of his patients by palpating the bumps on their heads. © Copyright Reed Business Information Ltd.

Keyword: Robotics
Link ID: 15350 - Posted: 05.21.2011

By Bruce Bower Faces of people who get tarred in the press or blasted behind their backs in snarky gabfests may literally stand out in the crowd. People find it particularly easy to see the faces of individuals about whom they’ve heard nasty or unpleasant gossip, reports a team led by psychologist Lisa Feldman Barrett of Northeastern University in Boston. “Encountering negative gossip about someone makes it easier to register that person’s face than neutral or positive gossip does,” says Feldman Barrett. Not only does the new study show that disapproving gossip quickly gets associated with a matching face, but that this connection operates outside conscious awareness, remarks cognitive neuroscientist Moshe Bar of Harvard Medical School. “A negative bias that originated in gossip made corresponding faces pop out in conditions where observers would have otherwise remained unconscious of those faces,” Bar says. A gossip-schooled eye for bad eggs provides social protection, the researchers propose, by extending opportunities to scrutinize potential liars and cheats. That argument fits with a previous proposal that gossip enabled the evolution of larger social groups in which people used spoken language to learn whom to befriend and whom to avoid. © Society for Science & the Public 2000 - 2011

Keyword: Attention; Emotions
Link ID: 15349 - Posted: 05.21.2011

by Ann Gibbons While dinosaurs ruled the world some 200 million years ago, a group of nocturnal, shrewlike proto-mammals unwittingly sniffed out a strategy for survival that eventually led to the evolution of larger brains. Fossil skulls of two ancient, mammal-like reptiles suggest that natural selection for a keener sense of smell was the initial spur behind bigger brains in early mammals, according to a report online today in Science. “Mammals didn’t get our larger brains for thinking,” says co-author Zhe-Xi Luo, a paleontologist at the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania. “We got it for a more urgent and more basic need—our sense of smell was far more important.” Birds and mammals have brains that are up to 10 times larger, relative to body size, than those of reptiles and other animals. Why? Some researchers have proposed that the early, nocturnal mammals evolved larger brains to boost their hearing, because sight was less important at night. Others have suggested that mammals’ brains are proportionately larger because as many early mammals evolved smaller bodies, their brains failed to shrink to scale. By reconstructing the two oldest known skulls of proto-mammals—fossils of Morganucodon and Hadrocodium discovered in the famed Lufeng Formation in Yunnan, China, in 1986—Luo and colleagues found clues to how the mammalian brain began to enlarge. The researchers scanned the skulls with computed tomography (CT) scans, creating three-dimensional, virtual endocasts of the brain, based on the impressions brain tissue and spaces left on the inside of the skull. That gave them a detailed view of the surface of the brain and the nasal cavities. © 2010 American Association for the Advancement of Science.

Keyword: Evolution; Chemical Senses (Smell & Taste)
Link ID: 15348 - Posted: 05.21.2011

By DENISE GRADY A young man paralyzed by an injury to his spinal cord has regained the ability to stand for short periods, take steps with help and move his legs and feet at will, with the help of an electrical stimulator implanted in his lower back. Rob Summers, 25, paralyzed for five years, regained some ability to stand after surgeons implanted electrodes in the lower part of his back to stimulate his spinal cord. The device is experimental and not available to other patients, and because it has been studied in only one person it is not known whether it would work as well in other people with different types of spinal injury. But the researchers say that scientifically the work is an important advance, because it shows that a bit of electrical stimulation can unlock the ability of the spinal cord to control movement — even if its signals from the brain have been cut off by injury. Similar findings had been made in animals. “It’s been thought that the brain controls all our movement,” said Susan Harkema, research director at the Kentucky Spinal Cord Injury Research Center in Louisville and the lead author of an article about the research being published online on Thursday in the journal Lancet. “But the spinal cord is the primary controller.” © 2011 The New York Times Company

Keyword: Regeneration; Robotics
Link ID: 15347 - Posted: 05.21.2011

By Jesse Bering There are so many obscure specializations, subspecializations and subcortical subspecializations within the brain sciences that even the sharpest brain has scarcely enough brainpower to learn everything there is to know about itself. But if there's one fact that the teacup-Yorkie-sized prune in your head might want to ponder, it's that it shares a peculiar past with something considerably lower in your anatomy—your genitalia. I don't mean that our brains and reproductive organs share some embryological or evolutionary history, but rather that they were once (and, to some extent, still are) entwined in the language of the body. What this odd story reveals is that the ancient anatomists were major dickheads. We all were, back then. Régis Olry, of the University of Quebec, and Duane Haines, of the University of Mississippi, brought the whole sordid tale to light in an intriguing pair of articles for the Journal of the History of the Neurosciences. These "historians of neuroanatomy" (yes, there is such a profession, and we should be grateful for it) reviewed a very old, circuitous medical literature and found that the human brain was once described as comprising its very own vulva, penis, testicles, buttocks, and even an anus. In fact, part of the cerebrum is still named in honor of long-forgotten whores. In their first article from 1997, epochs ago in academic terms, Olry and Haines revealed the surprising origins of the term "fornix." For those illiterate in neuroanatomy, which I'll assume is 99.9 percent of you, the fornix is a fibrous, arching band of nerve fibers that connects the hippocampus and the limbic system, and spans certain fluid-filled chambers of the brain known as ventricles. You'd have numerous and noticeable problems if your fornix weren't functioning properly, including serious impairments in spatial learning and overall navigation. © 2011 The Slate Group, LLC

Keyword: Miscellaneous
Link ID: 15346 - Posted: 05.21.2011

by Carl Zimmer In the 1940s, the Nobel prize–winning neurobiologist Roger Sperry performed some of the most important brain surgeries in the history of science. His patients were newts. Sperry started by gently prying out newts’ eyes with a jeweler’s forceps. He rotated them 180 degrees and then pressed them back into their sockets. The newts had two days to recover before Sperry started the second half of the procedure. He sliced into the roof of each newt’s mouth and made a slit in the sheath surrounding the optic nerve, which relays signals from the eyes to the brain. He drew out the nerve, cut it in two, and tucked the two ragged ends back into their sheath. If Sperry had performed this gruesome surgery on a person, his patient would have been left permanently blind. But newts have a remarkable capacity to regrow nerves. A month later Sperry’s subjects could see again. Their vision, he wrote, “was not a blurred confusion.” When he dangled a lure in front of one of the newts, the creature responded with a quick lunge. It was a peculiar sort of lunge, though: The animal looked up when the lure was held below and down when it was dangled overhead. Sperry had turned the newt’s world upside down. The experiment revealed that nerve cells, or neurons, possess a tremendous capacity for wiring themselves. Neurons grow branches known as dendrites for receiving signals, and sprout long outgrowths called axons to relay the signals to other neurons. Axons in particular can travel spectacular distances to reach astonishingly precise targets. They can snake through the brain’s dense thicket, pushing past billions of other neurons, in order to form tight connections, or synapses, with just the right partners. © 2011, Kalmbach Publishing Co.

Keyword: Development of the Brain; Regeneration
Link ID: 15345 - Posted: 05.19.2011

Scientists believe they are a step closer to being able to read people's minds after decoding human brainwaves. Glasgow University researchers asked volunteers to identify different emotions on images of human faces. They then measured the volunteers' resulting brainwaves using a technique called electroencephalography (EEG). Once researchers compared the answers to the brainwaves recorded, they were able to decode the type of information the brainwaves held relating to vision. The research was carried out by the university's institute of neuroscience and psychology. Six volunteers were presented with images of people's faces, displaying different emotions such as happiness, fear and surprise. On different experimental trials, parts of the images were randomly covered so that, for example, only the eyes or mouth were visible. The volunteers were then asked to identify the emotion being displayed. The participants' brainwaves were measured using EEG which allowed the researchers to identify which parts of the brain were active when looking at different parts of the face. BBC © 2011

Keyword: Brain imaging
Link ID: 15344 - Posted: 05.19.2011

By Laura Sanders Wiping out chronic pain in the lower back doesn’t just dull the agony. It allows the brain to recover, too. Six months after people’s backaches were eased, their brains showed fewer signs of the abnormalities that accompany chronic pain, a new study shows. This brain recovery is “a concrete message that certainly brings hope and relief to those suffering from this condition,” says UCLA neuroscientist Dante Chialvo. In the study, neuroscientist Laura Stone of McGill University in Montreal and colleagues scanned the brains of people who had experienced back pain for at least a year. Compared to healthy controls, chronic pain sufferers had thinning in the dorsolateral prefrontal cortex, a brain region that’s been linked to pain modulation. This region also showed abnormal activity when people with chronic back pain took a simple cognitive test while in a brain scanner, the team found. But six months after treatment with either spine surgery or pain-relieving injections, scans revealed that the pain sufferers’ brains bounced back. Their thin dorsolateral prefrontal regions grew larger, and their brain activity began to look more normal. These brain changes depended on the level of pain relief: The less pain a person reported after treatment the greater the improvement, the team reports in the May 18 Journal of Neuroscience. © Society for Science & the Public 2000 - 2011

Keyword: Pain & Touch
Link ID: 15343 - Posted: 05.19.2011

By Christof Koch The ancient debate surrounding the existence of free will appears unresolvable, a metaphysical question that generates much heat yet little light. Common sense and volumes of psychological and neuroscientific research reveal, however, that we are less free than we think we are. Our genes, our upbringing and our environment influence our behaviors in ways that often escape conscious control. Understanding this influence, the advertisement industry spent approximately half a trillion dollars worldwide in 2010 to shape the buying decisions of consumers. And extreme dictatorships, such as that in North Korea, remain in power through the effective use of insidious and all-pervasive forms of propaganda. Yet nothing approaches the perfidy of the one-celled organism Toxoplasma gondii, one of the most widespread of all parasitic protozoa. It takes over the brain of its host and makes it do things, even actions that will cause it to die, in the service of this nasty hitchhiker. It sounds like a cheesy Hollywood horror flick, except that it is for real. We know that illness in general can slow us down, incapacitate us and, in the worst case, kill us. Yet this organism is much more specific. Natural selection has given rise to pathogens that infiltrate the nervous system and change that system’s wiring to achieve its ultimate purpose, replication—like a computer virus that reprograms an infected machine. Such is the case with T. gondii. It sexually reproduces only in the intestines of cats yet can maintain itself indefinitely in any warm-blooded animal. Infected cats shed millions of their oocysts in their feces. Taken up by all kinds of animals, including dogs, rodents and humans, they infect muscle and the brain to escape attacks by the host’s immune system. © 2011 Scientific American,

Keyword: Attention
Link ID: 15342 - Posted: 05.19.2011

By Jamie Horder The search for the genetic roots of psychiatric illnesses and behavioral disorders such as schizophrenia, autism and ADHD has a long history, but until recently, it was one marked by frustration and skepticism. In the past few years, new techniques have begun to reveal strong evidence for the role of specific genes in some cases of these conditions but in a way few people expected. To understand what makes the new discoveries so novel, it’s necessary to appreciate how our genes can go wrong. The human genetic code can be thought of as an encyclopedia in multiple volumes. Our normal genome contains 46 chromosomes, so that’s 46 volumes. Each chromosome is a long string of the chemical DNA and the information is “written” in the form of a molecular alphabet with just four letters: A, T, C and G. There are three ways in which something can go wrong here. First, a whole chromosome can be either missing or duplicated. This drastic change is almost always fatal. (The exceptions include Downs Syndrome.) Second, single-nucleotide polymorphisms (SNPs, or “snips” as everyone calls them) are when a single base-pair is different, corresponding to a misprinted character. Finally, copy-number variants (CNVs) are when a stretch of DNA is either missing (deleted), or repeated (duplicated), a bit like a page that’s either fallen out or been printed twice. As you can imagine, CNVs tend to be more serious than SNPs, because they affect more of the DNA. This is only a general rule, however. There are plenty of serious SNPs, and plenty of harmless CNVs. It all depends on where they happen, and whether they interfere with important genes. © 2011 Scientific American

Keyword: Schizophrenia; Genes & Behavior
Link ID: 15341 - Posted: 05.19.2011

Adam Kepecs A surprising view has been gathering momentum in neuroscience: most of our thoughts and actions are driven by unconscious brain processes that are hidden from conscious introspection. So if consciousness is rarely in the driver's seat, and if we cannot choose our genes or the childhood experiences whose interactions form our brains, then are we responsible for our actions? In Incognito, accomplished neuroscientist David Eagleman — author of the best-selling short-story collection Sum (Canongate, 2010) — examines this gap between our conscious and unconscious selves. He offers a whirlwind of stories, from visual illusions and sleep-walking killers to ovulating strippers, all carefully chosen to drive home his main point that our brains “neurally preordain” us to make decisions. As is common in books aimed at a general readership, the intriguing and sometimes bizarre case studies create a tension between journalistic musings and more detailed arguments. Although specialists may feel that the balance tilts toward the journalistic, Eagleman's expertise comes through. Since Sigmund Freud's famous psychological framing of the unconscious in the late nineteenth century, modern neuroscience has shown that most processing in the brain is unconscious. We are unaware of routine processes and have little insight into our choices and preferences. For instance, men unknowingly prefer photographs of women with dilated pupils, presumably because male brains evolved algorithms to recognize pupil dilation as an indicator of sexual arousal. In another experiment, people's descriptions of the strategies they used to make simple economic decisions differed from the rules that they actually used, suggesting that their conscious explanations were formed post hoc and without access to their decision-making process. Through such examples, Eagleman demonstrates that unconscious processes can be clever, adaptive and even outperform the best computer algorithms. © 2011 Nature Publishing Group

Keyword: Attention
Link ID: 15340 - Posted: 05.19.2011